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Observación experimental del efecto Hall anómalo cuántico en un aislante topológico magnético
Cui-Zu Chang1, Jinsong Zhang, Xiao Feng
1State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, China.
Science (New York, N.Y.)
|March 16, 2013
Resumen
Los investigadores observaron el efecto Hall anómalo cuántico (QAH) en aislantes topológicos magnéticos dopados con cromo. Este avance en la física de la materia condensada allana el camino para nuevos dispositivos electrónicos de baja potencia.
Área de la Ciencia:
- Física de la materia condensada Física de la materia condensada Física de la materia condensada Física de la materia condensada Física de la materia condensada
- Ciencia de los materiales ciencia de los materiales.
- Spintronics es una empresa de Spintronics.
Sus antecedentes:
- El efecto Hall anómalo cuántico (QAH), una conductancia Hall cuantizada sin campos magnéticos externos, se predice teóricamente en aislantes topológicos magnéticos.
- La realización experimental del efecto QAH se ha visto obstaculizada por los desafíos en la síntesis de materiales y el logro de las condiciones necesarias.
Objetivo del estudio:
- Para observar experimentalmente el efecto Hall anómalo cuántico (QAH) en un sistema material realista.
- Investigar las propiedades de las películas delgadas dopadas con cromo (Bi,Sb) 2Te3 como posibles candidatos para la realización del efecto QAH.
Principales métodos:
- Fabricación de películas delgadas de cromo dopado (Bi,Sb) 2Te3.
- Mediciones de transporte eléctrico, incluida la resistencia anómala de Hall y la resistencia longitudinal, bajo diferentes tensiones de puerta y campos magnéticos.
Principales resultados:
- Observación del efecto QAH a cero campo magnético en las películas delgadas dopadas con cromo (Bi,Sb) 2Te3.
- La resistencia anómala de Hall alcanzó el valor cuantizado de h/e ((2) con una caída significativa en la resistencia longitudinal.
- La resistencia longitudinal desapareció bajo un fuerte campo magnético, mientras que la resistencia de Hall permaneció cuantizada.
Conclusiones:
- La realización experimental del efecto QAH en cromo dopado (Bi,Sb) 2Te3 proporciona una plataforma viable para el estudio de este fenómeno.
- Este logro abre caminos para el desarrollo de la próxima generación de dispositivos electrónicos de bajo consumo de energía basados en materiales topológicos.
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